Reduced brain serotonin transporter availability in major depression as measured by [123I]-2 beta-carbomethoxy-3 beta-(4-iodophenyl)tropane and single photon emission computed tomography

BACKGROUND: Prior research has suggested reductions in the density of serotonin transporter (SERT) binding sites in blood platelets and post-mortem brain tissue of depressed patients. We sought to determine whether patients with unipolar major depression have diminished SERT availability as assessed by both brainstem [123I] beta-CIT SPECT and platelet [3H]paroxetine binding. METHODS: Drug-free depressed and healthy subjects were injected with 211 +/- 22 MBq [123I] beta-CIT and imaged 24 +/- 2 h later under equilibrium conditions. A ratio of specific to nonspecific brain uptake (V3" = (brainstem-occipital)/occipital), a measure proportional to the binding potential (Bmax/Kd), was used for all comparisons. RESULTS: Results showed a statistically significant reduction in brainstem V3" values in depressed as compared to healthy subjects (3.1 +/- .9 vs. 3.8 +/- .8, p = .02). Platelet [3H]paroxetine binding was not altered (Bmax = 2389 +/- 484 vs. 2415 +/- 538 fmol/mg protein, p = .91) and was not significantly correlated with brainstem [123I] beta-CIT binding (r = -0.14, p = .48). CONCLUSIONS: These data are the first to suggest reductions in the density of brain SERT binding sites in living depressed patients. These findings provide further support for a preeminent role for alterations in serotonergic neurons in the pathophysiology of depression.     

The multifarious spectrum of ischemic left ventricular dysfunction: relevance of new ischemic syndromes

Ischemic heart disease, once limited to a number of well defined entities such as angina of effort, unstable angina, and myocardial infarction, must now be regarded as a much more complex and elusive entity. Silent ischemia was the first of the new ischemic syndromes to be described. Recently, three further new syndromes have been added, namely stunning, hibernation and preconditioning. All three have one common theme--they can be related to ischemia and reperfusion. In stunning, there is post-reperfusion mechanical dysfunction that recovers. In hibernation, there is prominent contractile dysfunction, apparently out of proportion to the reduction in coronary flow, and the recovery upon reperfusion is good. In preconditioning, severe ischemia followed by reperfusion protects against subsequent ischemia which may modify the severity of ischemic damage in the other ischemic syndromes. Ischemic LV dysfunction as found in post-infarct patients and in the absence of any simple relation to reperfusion, can be either diastolic or systolic or both in nature. In ischemic LV diastolic dysfunction without major systolic dysfunction, calcium antagonists may be appropriate therapy which could point to a role for abnormalities in the regulation of cytosolic calcium. It is proposed that there is potentially a mixed post-infarct syndrome, which may comprise one or more of the new ischemic syndromes (silent ischemia, stunning, hibernation, and preconditioning), as well as a varying degree of systolic and/or diastolic dysfunction. The basis of the systolic dysfunction is, at least in part, post-infarct LV remodeling. Several of these entities could overlap in the same patient. The term "mixed post-infarct ischemic syndrome" is suggested to describe this condition.     

Bin Packing with Rejection Revisited

We consider the following generalization of bin packing. Each item has a size in (0,1] associated with it, as well as a rejection cost, that an algorithm must pay if it chooses not to pack this item. The cost of an algorithm is the sum of all rejection costs of rejected items plus the number of unit sized bins used for packing all other items. We first study the offline version of the problem and design an APTAS for it. This is a non-trivial generalization of the APTAS given by Fernandez de la Vega and Lueker for the standard bin packing problem. We further give an approximation algorithm of an absolute approximation ratio 3/2, where this value is best possible unless P=NP.     

Two-dimensional online bin packing with rotation

In two-dimensional bin packing problems, the input items are rectangles which need to be packed in a non-overlapping manner. The goal is to assign the items into unit squares using an axis-parallel packing. Most previous work on online packing concentrated on items of fixed orientation, which must be assigned such that their bottom side is parallel to the bottom of the bin. In this paper we study the case of rotatable items, which can be rotated by ninety degrees. We give almost tight bounds on the (asymptotic) competitive ratio of bounded space bin packing of rotatable items, and introduce a new unbounded space algorithm. This improves the results of Fujita and Hada.     

Selfish Bin Packing

Following recent interest in the study of computer science problems in a game theoretic setting, we consider the well known bin packing problem where the items are controlled by selfish agents. Each agent is charged with a cost according to the fraction of the used bin space its item requires. That is, the cost of the bin is split among the agents, proportionally to their sizes. Thus, the selfish agents prefer their items to be packed in a bin that is as full as possible. The social goal is to minimize the number of the bins used. The social cost in this case is therefore the number of bins used in the packing.     

Learning to Be Thoughtless: Social Norms and Individual Computation

This paper extends the literature on the evolution of norms with anagent-based modelcapturing a phenomenon that has been essentially ignored, namely thatindividual thought – orcomputing – is often inversely related to the strength of a social norm.Once a norm isentrenched, we conform thoughtlessly. In this model, agents learn how tobehave (what normto adopt), but – under a strategy I term Best Reply to Adaptive SampleEvidence – they also learnhow much to think about how to behave. How much they are thinking affects howthey behave,which – given how others behave – affects how much they think. Inshort, there is feedbackbetween the social (inter-agent) and internal (intra-agent) dynamics. Inaddition, we generate thestylized facts regarding the spatio-temporal evolution of norms: localconformity, global diversity,and punctuated equilibria.     

Electrodynamics of a low-pressure electrode microwave discharge

Results are given of self-consistent two-dimensional simulation of self-sustained steady electrode microwave discharge in a chamber at the end of central conductor of a coaxial line. The discharge parameters are calculated in the diffusion mode in hydrogen at pressures of 0.5, 2, and 8 torr and incident power of 30–200 W. The dependence of matching between the discharge chamber and delivery path on the geometric dimensions of the chamber is investigated in the presence of plasma. It is demonstrated that the length of central electrode is the key factor affecting the structure of plasma formation and its matching with the pumping wave. The maxima and minima of matching alternate when the central electrode is elongated by quarter wave. The maxima and minima of matching for the case of low pressure (< 2 torr) are shifted by λ/4 relative to those for high pressure (> 2 torr). The problem of maximal energy input to the discharge region at the end of antenna-type electrode is analyzed. It is demonstrated that a restriction exists on the maximal energy input to such a discharge (and, accordingly, on the size of plasma formation). These restrictions are associated either with the runaway of discharge toward the generator or with the ignition of discharge in the region of entry of antenna into the chamber.     

Can we trust PRA?

The Fault-Tree/Event-Tree method is widely used in industry as the underlying formalism of probabilistic risk assessment. Almost all of the tools available to assess Event-Tree models implement the ‘classical’ assessment technique based on minimal cutsets and the rare event approximation. Binary decision diagrams (BDDs) are an alternative approach, but they were up to now limited to medium size models because of the exponential blow up of the memory requirements. We have designed a set of heuristics, which make it possible to quantify, by means of BDD, all of the sequences of a large Event-Tree model coming from the nuclear industry. For the first time, it was possible to compare results of the classical approach with those of the BDD approach, i.e. with exact results. This article reports this comparison and shows that the minimal cutsets technique gives overestimated results in a significant proportion of cases and underestimated results in some cases as well. Hence, the (indeed provocative) question in the title of this article.     

Alcoholics Anonymous and Relapse Prevention as Maintenance Strategies After Conjoint Behavioral Alcohol Treatment for Men: 18-Month Outcomes.

Ninety men with alcohol problems and their female partners were randomly assigned to 1 of 3 outpatient conjoint treatments: alcohol behavioral couples therapy (ABCT), ABCT with relapse prevention techniques (RP/ABCT), or ABCT with interventions encouraging Alcoholics Anonymous (AA) involvement (AA/ABCT). Couples were followed for 18 months after treatment. Across the 3 treatments, drinkers who provided follow-up data maintained abstinence on almost 80% of days during follow-up, with no differences in drinking or marital happiness outcomes between groups. AA/ABCT participants attended AA meetings more often than ABCT or RP/ABCT participants, and their drinking outcomes were more strongly related to concurrent AA attendance. For the entire sample, AA attendance was positively related to abstinence during follow-up in both concurrent and time-lagged analyses. In the RP/ABCT treatment, attendance at posttreatment booster sessions was related to posttreatment abstinence. Across treatment conditions, marital happiness was related positively to abstinence in concurrent but not time-lagged analyses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)